The infection spreads through the Eustachian tube to the middle ear. The risk of contracting an infection is higher if the Eustachian tube is small or does not work efficiently, which is often the case with small children.

Ear infections may also be caused by childhood illnesses, such as measles.

Ovarian cancer is most common in menopausal women (over 50 years of age). It is rare in women under 40..
As far as we know, ovarian cancer cannot be prevented. But women who have used oral contraceptives in the past have a reduced risk of ovarian cancer compared to women who have never used them.
Rarely, ovarian cancer can run in families and there may be a genetic defect to explain this. Genetic counselling and testing is available from specialist centres.